Problem: Solve for $n$ : $-24 = n - 12$
Explanation: Add $12$ to both sides: $ \begin{eqnarray} \\ \hphantom{-24 {+ 12}} &\hphantom{=}& \hphantom{n} \\ -24 &=& n - 12 \\ \\ {+12} && {+12} \\ \end{eqnarray} $ $ \begin{eqnarray} \\ -24 {+ 12} &=& n \\ \end{eqnarray} $ Simplify. $ n = -12$